Bending machines



May 24, 1960 B. GREEN szunmc MACHINES '7 Sheets-Sheet 1 INVENTOR. EE 8.GREEN v I i I Arm/avers MW m,

Filed June 10, 1958 L. B. GREEN May 24, 1960 NDING MACHINES 7Sheets-Sheet 3 Filed June 10, 1958 m hkr///////////Vv/////////////////////////////////////flflfl mm m. w B s a,4rra NEYS May 24, 1960 L. B. GREEN BENDING MACHINES '7 Sheets-Sheet 4Filed June 10, 1958 IN VENTOR. [as 3 GREEN ATTORNEYS W @y fi May 24,1960 1.. B. GREEN SENDING MACHINES 7 Sheets-Sheet 6 Filed Juna 10, 1958I N VE N TOR [6 15. GREEN I flrrcwA/em I i n WMW United States PatentBENDING MACHINES Lee :3. Green, 20280 Parklane Drive, Rocky River 16,Ohio Filed June 10, 1958, Ser. No. 741,154

17 Claims. (Cl. 153-46) This invention relates to metal bending machinesand, more particularly, to bending machines of the kind having clampingdies for clamping a workpiece therebetween and a bending die rockablerelative "tonne of the clamping dies for bending portionsof: theworkpiece around the latter. "Machine's o'f'tliis kind have beenparticularly useful in carrying out bending operations on workpieceshaving web and flange portions by bending the web portion out of its ownplane and by bending the flange portion or portions within their ownplanes, and have accomplished bending operations of this character in ahighly satisfactory manner and substantially without buckling of theflange portions and usually Without need for notching of the flangeportions.

When the bend to be made in such a workpiece is a relativelysmall-radius bend, the operation becomes more difficult because of theproblem of taking care of the excess metal in the flange portion of theworkpiece and the problem of appropriately controlling the movement ofthe rockable bending die. In previous bending -machines of this type thedesired control of the rockable bending die has usually been achieved bythe use of cooperating rack and gear members, as is exemplified in myearlier Patents 2,287,933 and 2,482,617, but when the radius of the bendto be made is small, it is not practical to employ such rack and gearmembers for controlling the bending die.

The present invention solves this problem and, as one of its objects,aims to provide a novel bending machine of the kind above referred toand wherein the bending die actuation is controlled by the use ofeccentric pivot means.

Another object is to provide a novel bending machine having eccentricpivot means for controlling the movement of a bending die actuated by aswingable member and wherein adjusting means for varying the oifsetrelation or eccentricity of the pivot means renders the machineadaptable for making bends of various difierent radii.

Other objects and advantages of this invention will be apparent in thefollowing detailed description and in the accompanying drawings forminga part of this specification and in which,

Fig. 1 is a plan view of a bending machine embodying this invention; I

Fig. 2 is a front elevation of the machine;

Fig. 3 is a vertical section taken through the machine on section line3--3 of Figs. 1 and 2;

Fig. 4 is a partial side elevation of the front portion of the machine;

Fig. 5 is a perspective view partly in section showing the die-carryingportions of the machine;

Fig. 6 is a partial vertical section taken through the die-carryingportions of the machine as indicated by section line 6--6 of Figs. 1 and5;

Fig; 7 is a partial vertical sectional view similar to that of Fig. 6but more or less diagrammatic in form and 2,937,686 Pattented =May 24,1960 'g'. "1'0 is a partial vertical section taken through the modifiedbending machine approximately as indicated by the section line 1010 ofFig. 9;

Fig. 11 is a sectional view taken through the bending die control meansas indictaed by section line ll-11 of Fig. 10; Y t

Fig. 12 is a partial vertical section corresponding with a portion ofFig, 10 and showing another position of the bending die and bending diecarrier;

Fig. 13 is a partial side elevation of a flanged workpiece to be bent;and

Fig. 14 is a partial side elevation of the workpiece after the bendingoperation thereon.

As one practical embodiment of the present'invention, the accompanyingdrawings show a bending machine 10 having a frame structure 11 and agroup of cooperating die members 12, 13 and 14 for performing a bendingoperation on a metal workpiece 15.

he die members consist of a pair of co-operating'work clamping dies,here represented by the die members 12 and 13, for receiving theworkpiece 15 therebetweenand of which the member 12 is a stationary diemember and the member 13 is a movable die member which ismovable towardand away from the member '12 for clamp- The movable die meming orreleasing the workpiece. ber 13 is also an anvil die for bending of theworkpiece thereagainst or therearound, as is explained hereinafter. The:movable die member 14 is a bending die which is rockable relative tothe anvil die 13 for causing the bending of the workpiece 15 against oraround the latter.

The frame structure 11 comprises a stationary main frame member or base17 having a transverse support portion or ledge 18 on which the diemember 12 is mounted, and swingably movable second'and third framemembers 19 and 20 which support and actuate the respective die members13 and 14.

Before proceeding with a more detailed description of the machine 10,the character of the workpiece 15 and the bending operation to beperformed thereon should be described. As representative of one formofworkpiece to be bent by the machine 10, Figs. 13 and 14 show theworkpiece 15 as comprising a sheet metal mem' her having a web portion22 and parallel longitudinal edge flanges 23 extending along the edgesthereof. Fig.

13 shows the workpiece 15 prior to the bending operation thereon. Fig.14 shows the workpiece after being bent by the dies of the machine 10and as having, for example, a small-radius bend 25 formed by such dies.

Because of the considerable amount of metal of the flanges 23 which mustbe taken care of for the successful performance of bending operations ofthis kind, particularly for such small-radius bending operations, theworkpiece 15 can be prepared for the bending operation by cuttingsuitable notches 26 in the fianges.- The notches 26 extend for only aportion of the depth of the flanges and, as shown in Fig. 13, theportions 27 of the flanges which lie nearest the web portion 22 are leftintact or unnotched. The notch 26 can be of a substantially right angleshape when the bend 25 to be made is a substantially right angle bend asshown in Fig. 14 and, in forming the notch, a portion of the flange ispreferably left to extend into the notch recess as aj'ointforming edgeor lip 28 for subsequent welding to the edge portion 29 at the oppositeside of the notch.

During the formation of the bend 25 the web portion 22 is bent out ofits own plane and the unnotched portions 27 of the flanges 23 are bentwithin the planes of the flanges. At the completion of the bend 25 thelips 28 of the flanges 23 will lie in an overlapping relation to theedge portions 29, as shown in Fig. 14. The overlapping lips 28 can besecured to the edge portions 29 by suit able welding operations, afterwhich the lips 28 can, if desired, be removed as excess metal as bymeans of a suitable grinding operation to leave the side faces of theflanges 23 in a smooth and flush condition at the location of the bend25.

Important advantages are realized from the use of the bending machine inproducing workpieces, such as the workpiece 15, having the bend 25therein. One of these advantages is that the unnotched portions 27 ofthe flanges 23 can be bent entirely within the planes of the flangeswithout buckling or wrinkling of these portions of the flanges. Whenthese unnotched portions 27 are thus bent within the planes of theflanges 23, the need for notching the flanges for their full depth isavoided and the bent workpiece will be of a much more smooth and regularshape at the location of the bend, and will be much stronger and morerugged then if the bend had been made by the use of notches of the fulldepth of the flanges.

Moreover, when the unnotched portions 27 of the flanges 23 are bent bythe machine 10 in the manner ex plained above, the need for performingany welding or grinding operations at or near the rounded apex 25 of thebend is avoided. To perform such welding and bending operations at, orclosely adjacent to, the apex portion 25 as would be necessary if thenotches 26 were of the full depth of the flanges 23, would be extremelydiflicult and time consuming because of the problem of obtaining asmooth and regular finished curvature for the apex portion.

Reverting now to the detailed description of the bending machine 10, itwill be observed that the main frame member or base 17 includes a bottomplate 32 on which the machine is adapted to stand or rest, an uprightfront wall 33, and a pair of upright side walls 34 and 35. The frontwall 33 extends between and is connected to the side walls 34 and 35adjacent the front end of the machine. An L-shaped connecting bar 36extends between and is connected with the side walls adjacent the rearend of the machine and at an elevation above the bottom plate 32, asshown in Fig. 3. A longitudinal, channel-shaped support 37, comprisingangle bars 37 and 37 extends longitudinally of the main frame member 17and has its front end attached to the front wall 33 as by means ofscrews 38 and has its rear end attached to the transverse bar 36 as bymeans of suitable screws 39.

The swingably mounted frame member 19 is in the form of a yoke, as shownin Fig. 1, comprising a transverse front bar 41 and a pair of yoke arms42 and 43 connected to the ends of the transverse bar and extendingrearwardly of the main frame member 17 adjacent the side walls 34 and 35of the latter. The frame member 19 is swingably mounted on the mainframe member 17 by having the rear ends of its yoke arms 42 and 43fulcrumed on the side walls 34 and 35 by means of pivot pins 45 and 46carried by such side walls.

The transverse front bar 41 of the frame member 19 forms a mount onwhich the anvil die member 13 is located and to which this die member issecured as by means of suitable attaching bolts 47. The swingingmovements of the frame member 19 are guided in the main frame member 17as by means of guide screws 49 and 50 adjustably mounted in the sidewalls 34 and 35 and having guide elements 52 on the inner ends thereofwhich are in sliding engagement with guide pads 53 provided on the sidesof the yoke arms 42 and 43.

The swingable frame member 19 is actuatable by suitable power meanswhich is here shown as comprising a double-acting fluid pressureresponsive cylinder device 54 and a transverse rock shaft 55. The rockshaft 55 has its opposite ends journalled in the side walls 34 and 35 bymeans of suitable support bearings 57 and 58 pro' vided on the latterand has a lower input lever 59 secured thereon at a point substantiallylongitudinally opposite an end of the cylinder device 54.

The rock shaft 55 has power output levers 60 and 61 secured thereon atpoints located just inwardly of the side walls 34 and 35 and whichlevers carry crank pins 62. The swingable end of the frame member 19 isconnected with the levers 60 and 61 by upright links 63 and 64 forimparting raising and lowering swinging movements to this frame memberin response to rotation of the rock shaft 55 in opposite directions. Thelinks 63 and 64 have their lower ends pivotally connected to the levers60 and 61 by the crank pins 62 of the latter and have their upper endsconnected to the frame member 19 by pivot pins 65 carried by the yokearms 42 and 43.

The actuating lever 59 for the rock shaft 55 is provided at the free endthereof with a crank pin 67 by which the outer end of the piston rod 68of the cylinder device 54 is pivotally connected with this lever. Theinner end of the piston rod 68 is connected with a suitable piston whichis movable in the cylinder device 54 in response to pressure fluid beingsupplied to, and exhausted from, opposite ends of this device throughsuitable conduit connections 71 and 72. At the end thereof remote fromthe piston rod 68, the cylinder device 54 is connected with thelongitudinal support 37 as by means of a suitable mounting bracket 73attached to the latter and a suitable pivot pin 74.

The frame memberZi is a swingable frame member or wing having atransverse plate-like support portion 76 extending between and connectedwith a pair of parallel upright side walls '77. The wing 20 alsoincludes an upright rear wall 78 having its upper transverse edgeportion connected with the rear edge portion of the support portion 76,and also having its opposite ends connected with the upright side walls77. The wing 28 also comprises a pair of yoke arms 80 and 81 by whichthe wing is swingably connected with the side walls 34 and 35 of themain frame member 17 and which arms have the side walls 77 of the wingattached thereto as by suitablescrews, or the like, 82.

The bending die 14 is actuated by the swinging movements of the wing 20,as will be further explained here inafter, although it is not mounteddirectly on the support portion 76 of the wing but on a die carrier orsocalled slip plate" 83 which has translatory movement relative to thesupport portion. The side walls 77 of the wing have top edge portions 84and 85 which extend above the support portion 76 and co-operate with thelatter in defining a guideway 86 in which the carrier 83 is movable andis retained by retainer strips or gibs 87 secured to the edge portions84 and 85 by screws 88 and overhanging the guideway. The carrier 83 isslidably supported in the guideway 86 by suitable bearing strips 89provided on the support portion 76 of the wing.

As shown in Fig. 5, the stationary work supporting and clamping diemember 12 is of a shape appropriate for supporting and clampingco-operation with the workpiece 15 and, in this instance, has a flatportion 16 against which the Web 22 is adapted to be clamped by theanvil die 13 and also has hardened L-shaped wear strips 21 whose uprightflange portions 21 are adapted to overlap the side faces of the anvildie for confining the flanges 23 against the latter.

The anvil die 13 is of an appropriate shape for clamp ing the workpiece15 against the die member 12 and has side faces 24 against which theflanges 23 are confined by the portions 21 of the latter die member. Theanvil die 13 also has a curved portion, in this case, a curved ing theworkpiece 15 around the anvil die. '83 has limited shifting movement inthe guideway 86 ina direction normal to the plane of thesupport portion76 to enable the bendingdie 14 to bepressed against ea-pawns priate forthe workpiece 15 and the bendingoperation to .be performed on thelatter, and is. mounted on the carrier 83 by suitable attaching bolts90. The bending .die I14 .is hereshown ashaving a fiat .portion 92 :forpressing the .web 22 of the workpiece against the anvil die13 andalsohas hardened L-shape'diwearstrips 93similar to those of the diemember 12. .The .strips '93 :have portions 693 which are adapted tooverlap the sides 24 ofthe'anvil 'die for confining the flanges .23:against such sides during 1 the bending operation.

During thebending operation performed by the bending die 14, this diememberis rocked against the anvil die 13 by-an upward swinging of thewing 20 for-bend The carrier the workpiece during the bendingoperation-by the action of compression springs' 94 provided in pockets95 of the wing and-which springs are effective-against the underside ofthe carrier through bearing pads 96 slidably engaged by-the latter.

In preparation for the bending .operation, theflanged workpieceisinserted into the=machine in overlying relation to the bending die 14and the-stationary die 12 is clamped against the latter by a downwardclosing movement imparted tothe anvil die 13 by the :swingableframemember 19. The initial position for the wing -2'0,'tl e carrier 83, andthe bending 'die '14 is that shown in Figs. 3 and 6 of thedrawings'in-which the carr ier 83 is located in front ofand-aligned-with the supportportion 18 of the main frame member .17 andthe die members 12 and 14 have their adjacent edges in cooperatingengagement at a parting line- 91. V

The bending operation is carried out by the abovementioned rocking ofthe bending-die "14 againstthe anvil die 13 while the latter is in itswork-clamping position shown in Fig. 3 and whichrocking'of the bendingdie is produced by a forward and upward swinging of the wing which theanvil die 13 is moved away from the lower clamping "die 12 to releasethe bent workpiece and to permit the insertion of another workpiece to'be bent.

Theswinging of the wing 20 to produce the-bending and return movementsof the die 14is produced by a suitable power means which is here shownas being a double-acting fluid pressure'responsive cylinder device-98.The cylinder device 98 ismounted on the support-37 of the main framemember 17 and includes a 'slidable crosshead 99 connected with the outerend of a piston rod 100. The inner end of the piston rodris connectedwith a piston which is movable in opposite directions in the cylinderdevice 98 in response to fluid pressure supplied to, and exhausted from,the cylinder device through conduit members 102 and 103.

Movement supplied by the cylinder device '98 is transmitted to the wing20 through a pair of curved connecting links 105 whose rear ends areconnected tothe crosshead 99 We pivot pin 106, and whose forward endsare connected to the wing by the pivot pin 107 of a suitable bracket108. During the bending stroke thereof, the wing 20is swung forwardlyand upwardly from its full line initial position shown in Figs. 3 and 4to the broken line position 20* of Fig. 4 and, during the return strokeof the wing, it is swung forwardly and downwardly to return the same tothe initial position.

It is important that the bending die 14 occupy the initial positionmentioned above and shown in the drawaings when' the workpiece :15 is,placed inthemachine; and

this positioning of the bending dieis obtained by=cooperation .of thecarrier 83 with the support portion 18 of the main frame member 17. Forthis purpose, the support .portion 18 is provided across the frontedgethereof with an abutment portion 110 in the form of aforwardly-projecting lip having a bevel on the underside thereof.Theicarrier 83 is provided across the rear edge thereofwith a locatingportion '111 which is engageable with the abutment'portion 110 andincludes a projecting flangehaving .aibevel thereon which engages andmatches withcthebevelon the underside of the abutment portion,

The correct initial positioning of the as shown in :Fig. 3. bendingdiexl'4is obtained when the wing 20 has been returned'to the positionwhere the locating portion 111 of the carrier 83 is in such matchedengagement with the abutment portion 110 of the frame member 17.

The ipivotmeans, by which the'wing 20 and the .cariierf83 are swingablyfulcrumed on the frame structure 11 is an important part of the presentinvention by whichproper control of the carrier and of the bending die.14 is :achieved during the bending operation, and which :pivot meanswill be described next. The pivot means for the wing 20 comprises a pairof main pivot pins 113 and 114 carried by the side walls 34 and 35 I andon which the eye-shaped end portions 115 and 116 of the yoke arms 80 and81 of the wing are swingably journalled. The pivot means for the carrier83 comprises a pair of auxiliary pivot pins 117 and 118 which are alsocarried bythe side walls 34 and 35 but are in an offset or eccentricrelation to the pivot pins 113 and 114. As shown in the drawings, thepivot'pins 113 and 114 for the yoke arms of the wing20 project from thewalls 34 and '35 on the outer'sides thereof, whereas the pivot pins 117and 118-for the carrier 83project from the inner sides of'these walls.

The main pivot pins 113 and 114 can be formed on the side walls '34 and35 but, as here shown, are'preferably in the .form of stem extensions ofmounting flanges 113 and'11'4 and project through suitable openings'ofthe side walls. The mounting flanges 113 and 114* are secured againstthe side walls 34 and 35 by suitable screws 119.

The pivot pins 117 and 118 for the carrier 83 can be formed asprojections on theside walls 34 and 35 but, in accordance with thepresent invention, are preferably separate from the side walls and areprovided by adapter members 120 and 121 which are mounted on such sidewalls.

The adapter members 120 and 121 are here shown as each comprising a diskportion 122 having a pivot pin secured to the side walls 34 and 35 or tothe mounting flanges 113 and 114 of the main pivot pins 113 and 114.

The pivot pins 113 and 114 for the yoke arms of the wing 20 are providedwith central openings through which the mounting stems 123 of theadapter members and 12,1 extend. Nut and washer'retaininge'lements 125and 126 are applied to the outer ends of the stems 123 for holding theadapter members 120 and 121 in their assembled position and also serveto retain the yoke arms 80 and 81 of the wing in their swingablyfulcrumed relation on the main pivot pins 113 and 114. The eccentricallyoffset relation between the main pivot pins 113, 114 and the auxiliarypivot pins 117, 118 provides 'oifset pivot axes 128, 129 about which thewing 20 and the carrier "83 are respectively swingable. The offsetrelation of the pivot axes 128' and 129 is illus- "7 trated in thedrawings, particularly in Figs. 3, and 6 and in the diagrammatic viewshown in Fig. 7.

The swingable connection of the carrier 83 with the pivot pins 117 and118 is provided with a pair of substantially L-shaped yoke members orbrackets 130 and 131 which are connected with the carrier by suitableattaching screws 132. The yoke members 130 and 131 comprise connectedbase and yoke arm portions 133 and 134 of which the arm portions 134have slot-like guideways 135 therein in which the pivot pins 117 and 118are received. The base portions 133 of the yoke members 130 and 131 areseated on the carrier 83 and are clamped thereagainst by the attachingscrews 132.

Because of the eccentric or offset relation of the pivot axes 128 and129, the carrier 83 will have a controlled movement during the swingingof the wing 20 which is produced by a reaction force developed betweenthe yoke arm portions 130 and 131 and their associated pivot pins 117and 118. The diagrammatic view of Fig. 7 graphically illustrates thecontrol movement to which the carrier 83, and the bending die 14supported thereby, are subjected during the bending stroke of the wing20 in response to the offset relation of the pivot axis 129 of thecarrier relative to the pivot axis 128 of the wing. Thus, as shown inFig. 7, the carrier 83 has a slower rate of actuation or lags behind thewing 20 due to the reaction force applied through the yoke arms 130 and131, during the forward and upward bending-stroke swinging movement ofthe wing. In other words, the carrier 83 has a backward movementimparted thereto relative to the wing 20 at the same time that thecarrier is being actuated by the forward and upward swinging movement ofthe wing.

To illustrate this lagging or relative backward movement of the carrier83, Fig. 7 shows successively different positions of the wing 20 whichare represented by successive swing lines 137, 138, 139 and 140 andwhich swing lines are spaced apart by increments of twenty-two andone-half degrees. The lagging or backward movement of the carrier 83relative to the wing 20 is represented by the successively differentpositions of the locating portion 111 of the carrier relative to theswing lines 137, 138, 139 and 140 and by the dimensional distance lines141, 142, 143 and 144 indicating the varying amounts by which thecarrier has lagged behind the wing.

The actuation of the bending die 14 by the wing 20 is controlled by thislagging or relative backward movement of the carrier 83 and causes thebending operation to be carried out on the workpiece 15 in such a mannerthat the excess metal in the unslotted portions 27 and the flanges 23 ofthe workpiece will be upset or otherwise distributed and, at the sametime, confined to the planes of the flanges so that the bending of theflanges is carried out smoothly and without buckling or wrinklingthereof. When the bending operation has been completed and the wing 20is swung back to its initial position shown in Fig. 3, the controlmovement imparted to the carrier 83 through the yoke members 130 and 131by reason of the offset relation of the pivot axis 129, causes thecarrier to be returned to its initial position in which its locatingportion 111 is in engagement with the abutment portion 118 of the framestructure.

The offset relation shown in the drawings between the pivot axes 128 and129 is appropriate for a bending operation for producing a bend of agiven radius of curvature as, for example, the bend 25 of the workpieceshown in Fig. 14. The machine 10 is readily adaptable, however, forproducing other bends of different radii of curvature. By providing thepivot pins 117 and 118 for the carrier 83 as portions of the adaptermembers 120 and 121, it will be observed that by substituting in themachine 10 other such adapter members having a different eccentricity oroffset relation for the pivot pins .117 and 118, these pivot pins willhave correspondingly different fulcrum point locations in the slots 135of the yoke arms 134 and the controlled actuation of the carnier 83 andthe bending die 14 will then be appropriate for producing bends havingradii of curvature corresponding with the eccentricities selected forthe pivot pins 117 and 118.

From the construction described above for the adapter members 120 and121, it will also be observed that these members are readily detachablefrom the side walls 34 and 35 of the bending machine 10, and that othersuch adapter members having a ditferent selected eccentricity for thepivot pins 117 and 118 can be readily assembled into the machine. Whensuch other adapter members are assembled into the machine, the pivotpins 117 and 118 thereof will have a different fulcrum point location inthe slots 135 of the yoke arms 134, such that for a bend having asmaller radius of curvature the fulcrum point location of the pivot pinsin the slots 135 will be relatively closer to the pivot axis 128 of thewing and for a bend having a larger radius of curvature the fulcrumpoint location of the pivot pins 117 and 118 in the slots 135 will berelatively more remote from the pivot axis 128.

It will be understood, of course, that when the machine 10 is beingadapted for making bends of other curvatures, other anvil dies will needto be substituted in the machine and, in each case, the anvil die to beused will be one whose edge portion 13 has a radius of curva turecorresponding with that of the bend desired to be made. If the bend tobe made is one having little or no radius, then the anvil die 13 will beone whose edge portion 13 is primarily a corner edge.

Since it is important that the carrier 83 and the bending die 14 startfrom and be returned to the initial position shown in Figs. 3 and 6, itis necessary that the yoke members 130 and 131 have an adjustableconnection with the carrier so as to properly accommodate the pivot pins117 and 118 of the different adapters 120 and 121 which may be selectedfor different desired radii of curvature. For the purpose of thisadjustable connection, the carrier 83 is provided with dovetail slots146 adapted to receive shiftable plate-like nuts 147 for the attachingscrews 132. The dovetail slots 146 include access openings 148 at oneend thereof of a size to permit insertion of the nuts 147 into theslots. By releasing the clamping action of the screws 132, the yokemembers 134 can be adjustably shifted on the carrier 83 to a positionappropriate for the eccentricity of the pivot pins 117, 118 of theparticular adapter members 120, 121 with which the machine 10 is thenbeing equipped.

When the yoke members 130 and 131 have been thus adjusted on the carrier83 to the setting appropriate for the pivot adapter members 120 and 121which have been installed in the machine, the clamping screws 132 aretightened so that these yoke members thereafter remain in a fixedposition on the carrier for the full cycle of the bending operation.

For the construction of the machine 10 as shown in Figs. 1 to 8inclusive of the drawings and described above, it will be accordinglyseen that the carrier 83 has a translatory movement relative to the wing20 and along the guideway 86 and that during the bending operation thewing will swing about the pivot axis 128 while the carrier S3 and thebending die 14 will swing about the offset pivot axis 129. The reactionforce, to which the carrier 83 is subjected during the bending operationby reason of the ofiset relation of the pivot axis 129, will cause theforward and upward swinging of the bending die 14 around the anvil die13 to take place at a relatively slower rate than the forward and upwardswinging of the wing 21 as explained above, but the return swinging ofthe wing will nevertheless always return the carrier 83 and the bendingdie 14 to their desired initial position shown in the drawings. Becauseof the relatively slower movement or lagging action of the carrier radii.on different workpieces desired to be bent. greater adaptability ofthebending machine 151 results 283 .andthe bendingdie .1-4 relativezqtoathe wing. during the bending operation, it will zhezseenthat;the:overlapping aportions '93 of :the bending die 14 will beeffective :to

hold :the .flanges 23 of theworkpiece .15 .for confining :the .unnotched.portions'27 thereof against wrinkling or buckling during the bending ofthe :flanges :within their .own planes.

Figs. 9110 .12 inclusive of the drawings show :amodified bendingmachine151 which is ofrthe sameconstruc- ;tion .as the bending machine withrespect :to'the gen- .eral organization thereof :and which uses thesame.dies 12, 13 and 14 for producing similar bending operations on aworkpiece 152 which is of the same character as the workpiece .15. Themodified tbending machine 151, 'however, is more :readilyadaptableiorbe'nds of :diirerelzlnt T is from a dirierentand novel .form .ofpivotmeans 153 em- :ployed in the machine by whichdiiferent eccentricitiesfor the pivot pins of thebending die carrier can L-beobtained withoutneed for removing'and substituting steps to becarried outwith respect topivot'pin adapter members such'as the adapter members :120 and 121described abovein the machine 10.

-In the modified machine 151 a bending @die carrier or slip rplate.8'3is provided and :has yoke members 130 and 131 thereon whose yoke arms134 are provided twiththe guide slots 135 for receiving pivot pins 153.These pivot pinsprovide a pivot axis $54 which is offset from a pivotaxis .155 of the wing 20. The pivot pins 153 are preferablynot.fulcrumeddirectly in the slots 135 but are provided with crossheadblocks 156 which aiford a larger bearing surface area with the sidewalls of the slots.

Since the same pivot pin adjusting structures 153 are provided :at bothsides of thecarrier 83, only one of these structures need'be describedin detail.

To render the pivot pin 153 readily adjustable to differenteccentricities relative to the pivot axis 155 of the wing, this pivotpin is mounted on-a slide 1'56which is movable in a {dovetail guideway157 formed in a mounting plate 158. The plate 158 is mounted on anupright side wall 35 of the machine 151 as by means of screws 159. Theslide 156 is provided with a threaded opening 160 and is adjustablymovable in the guideway 157 by means of an adjusting screw *161 engagedin the threaded opening.

The screw 161 is provided at the outer end thereof with a knurledactuating knob 162 and ,is rotatably supported and axially 'held 'in asupport plate 163 secured on a bracket extension 164 of the mounting.plate 158.

Upon rotation of the screw 161 in one direction or the other, the slide156 will be moved along the guideway 157 and the pivot pin 153 will beshifted toward or away from the main .pivot axis 1'55 to the desiredeccentric setting. "During such shifting of the pivot pin 1153 by theadjusting screw 161, the yoke member 130 'is adjustably shiftable on thecarrier .83 by reason of alloosened condition of theclamping screws.132. "The adjustnient of the pivot pin 153 to the desired eccentricposition by the adjusting screw 161 thus also causes adjust- ,ableshifting of the yoke member 130 along {the carrier 83.

When the desired .settingforthe pivot pin 153 has been reached, theclamping screws 132 are tightened .to .conmet the yoke member 130 in afixed relation tto .the .carrier 83. To relieve the adjusting screw1610f the need to hold the slide 156 against further shifting along theguideway 157 after the desired setting for the pivot pin *face :of the.:slide.;1.56 :and zapplyclampingspressureitothe .esIide-inresponse totightening of the .screws 166,.

The functioning of the modified bending machinelgl in performing abending operation on the flanged work- 7 piece 152 :is substantially thesame as has already-been the particular offset ,relation'or eccentricityprovided for the pivot pin 153 of the carrier 83. The extent to whichthe carrier 83 has lagged behind-.thewing. 20 by thetime that thebending operation on the workpiece 152 iscompleted is represented bythedimensional distance line 170.

The mounting plate 58 is preferably provided with a graduated scale 172to indicate diiferent radii of curvature for which the pivot pins 153can beset bymovement of the slide 156 along the guideway 157. The heelend 156 of the slide cooperates with the graduations of the scale 172 toindicate the ,radius ,for which the slide has been adjusted by the screw1631.. Figs. .10 and l2 show the die 13 and'the setting of the pivot pin153 of the machine 151 as being for a bend of a larger. radius ofcurvature than that of the bend 25 being formed by the machine 10.

From the accompanying drawings and the foregoing for the bending diecarrier to thereby eliminate the need for the cooperating gear membersheretofore used for controlling the movements of the bending diecarrierand the bending die. It will now also be understood that the presentinvention providessuch a novel-construction for metal bending machineswherein the machines are readily adaptable for use in producing bends ofdifferent radii of curvature for different desired workpieces.

Although the novel bending machines of the present invention have beenillustrated and-described herein to a .somewhat detailed extent, it willbe understood, of course, that the invention is not to be regarded asbeing limited correspondingly in scope but includes all changes andmodifications coming within the terms of the claims hereof.

Having described my invention, I claim:

1. In abending machine, a frame structure'comprising stationaryandmovable frame members, a pair of relatively movable work clampingdies mounted on said frame members and adapted for clamping engagementwith opposite sides of a workpiece to be-bent and one of which dies isan anvil die, means for actuating'the movable framemember for causingsaid dies to clamp the workpiece, a third frame member having a guidewaythereon, first pivot means connecting said third frame member with saidstationary'frame ,member for swinging about a first pivot axis, mea nsfor causing theswinging of said third frame member, a carrier on saidthird frame member and movable thereon along said guideway, a bendingdie on said carrier and rockably movable 'relative to said anvil die forbending the workpiece against the latter in response to the swinging ofsaid third frame member, and control means associated with said "firstpivot'means and efiectiveon said carrier for controlling the movement ofthe latter along said guideway during the swinging of said third framemember, said control ,means comprising auxiliary pivot means connectingsaid carrier with said stationary frame member for swinging about asecond pivot axis :eccentrically ofiset from :said first pivot axis.

.2. A bending machineas defined in claim 1 and wherein ,said au giliarypivot means .comprises ;a .pair vof pivot "f1 members projecting fromsaid stationary frame member and a pair of slotted yokes connected withsaid carrier and fulcrumed on said pivot members. V

3. A bending machine as defined in claim 1 and wherein said controlmeans also comprises means effective on said auxiliary pivot means forvarying the eccentricity of the offset relation of said second pivotaxis.

4. A bending machine as defined in claim 1 and wherein said stationaryframe member has spaced walls thereon and said carrier has a pair ofspaced yokes thereon. and wherein said first pivot means comprises firstpivot members on said walls and said auxiliary pivot means comprisessecond pivot members having said yokes fulcrumed thereon, said secondpivot members being detachably connected with said walls.

5. A bending machine as defined in claim 1 and wherein said stationaryframe member has spaced walls thereon and said carrier has a pair ofspaced yokes thereon, and wherein said first pivot means comprises firstpivot members on said walls and said auxiliary pivot means comprisessecond pivot members, having said yokes fulcrumed thereon, said secondpivot members comprising mounting stems extending through said firstpivot members substantially coaxially of the latter and pivot pinsconnected with said stems in ofiset relation thereto and fulcrumablyengaged by said yokes.

6. In a bending machine, a frame structure comprising stationary andmovable frame members, a pair of relatively movable work clamping diesmounted on said frame members and adapted for clamping engagement withopposite sides of a workpiece to be bent and one of which dies is ananvil die, means for actuating the movable frame member for causing saiddies to clamp the workpiece, a third frame member having a guidewaythereon, pivot means on said stationary frame member and comprisingeccentrically offset first and second pivot pin portions providing twoparallel pivot axes, said third frame member being fulcrumed on saidfirst pivot pin portions for swinging about one of said pivot axes,means for causing the swinging of said third frame member, a carrier onsaid third frame member and movable thereon along said guideway, abending die on said carrier and rockably movable relative to said anvildie for bending the workpiece around the latter in response to theswinging of said third frame member, and means connected with saidcarrier and fulcrumed on said second pivot pin portions for swingingabout the other of said pivot axes, the co-operation of thelast-mentioned means with said second pivot pin portions being effectivefor moving the carrier along said guideway in response to the swingingof said third frame member.

7. In a. bending machine, a stationary first frame member having a diesupport including an abutment portion, a second frame member movabletoward and away from said first frame member, a pair of die members onsaid first and second frame members and adapted for clampingco-operation with a work-piece disposed between said die members, thedie member on said second frame member being an anvil die member,actuating means for moving said second frame member to cause said diemembers to clamp said workpiece, a third frame member having a guidewaythereon, a carrier adapted for movement along the guideway of said thirdframe member and having a locating portion engageable with said abutmentportion, pivot means on said stationary frame member and comprisingeccentrically offset first and second pivot pin portions providing twoparallel pivot axes, said third frame member being fulcrumed on saidfirst pivot pin portions for swinging about one of said axes and havingan initial position with the locating portion of said carrier inengagement with said abutment portion, means for swinging said thirdframe member through bending and return strokes for actuating saidcarrier and of which the bending stroke movement is in a directionaway'from said first frame member, a bending die on said 1 carrier andco-operable with said anvil die. member for bending the workpiece aroundthe latter during the bending stroke swinging of said third framemember, and means connected with said carrier and fulcrumed on saidsecond pivot pin portions for swinging about the other of said pivotaxes, the cooperation of the last-mentioned means with said second pivotpin portions being effective for controlling the rate of actuation ofthe carrier by said third frame member, said carrier having a resultingcontrol movement relative to the third frame member and along saidguideway in a direction toward said abutment portion during the bendingstroke movement of said third frame member.

8. Abending machine as defined in claim 7 and wherein the eccentricityand direction of ofiset between said first and second pivot pin portionsare such that the resultant movement of said carrier during the bendingstroke swinging of said third frame member is a movement in the samedirection as said third frame member but at a slower rate of movement.

9. A bending machine as defined in claim 7 for operation on a workpiecehaving web and flange portions to be bent and wherein the die member onsaid first frame member and said bending die have angularly disposedconfining portions adapted to overlap side portions of said anvil die inconfining relation to said flange portions.

10. A bending machine as defined in claim 7 for operation on a workpiecehaving web and flange portions to be bent and wherein the die member onsaid first frame member and said bending die have angularly disposedconfining portions adapted to overlap side portions of said anvil die inconfining relation to said flange portions, and wherein the eccentricityand direction of offset between said first and second pivot pin portionsare such that the resultant movement of said carrier during the bendingstroke swinging of said third frame member is a movement in the samedirection as said third frame member but at a slower rate of movement.

11. In a bending machine, a frame structure comprising stationary andmovable frame members, a pair of relatively movable work clamping diesmounted on said frame members and adapted for clamping engagement withopposite sides of a workpiece to be bent and one of which dies is ananvil die, means for actuating the movable frame member for causing saiddies to clamp the workpiece, a third frame member having a guidewaythereon, pivot means on said stationary frame member and comprisingeccentrically offset pivot pin portions providing two parallel pivotaxes, said third frame member being fulcrumed on certain of said pivotpin portions for swinging about one of said pivot axes, means forcausing the swinging of said third frame member, a carrier on said thirdframe member and movable thereon along said guideway, a bending die onsaid carrier and rockably movable relative to said anvil die for bendingthe workpiece around the latter in response to the swinging of saidthird frame member, and yoke means connected with said carrier andfulcrumed on others of said pivot pin portions for swinging of thecarrier about the other of said pivot axes, said yoke means beingeffective between said other pivot pin portions and said carrier formoving the latter along said guideway in response to the swinging ofsaid third frame member.

12. A bending machine as defined in claim 11 and wherein said yoke meanscomprises yoke members having bearing slots therein and fulcrumed onsaid other pivot pin portions by engagement of the latter in said slots,and wherein said yoke means is adjustably connected with said carrier.

13. In a bending machine, a frame structure comprising stationary andmovable frame members, a pair of relatively movable work clamping diesmounted on said frame members and adapted for clampingfengage- 13 mentwith opposite sides of a workpiece to be bent and one of which dies isan anvil die, means for actuating the movable frame member for causingsaid dies to clamp the workpiece, a third frame member having a guidewaythereon, pivot means on said stationary frame member and comprisingeccentrically ofiset first and second pivot pin portions providing firstand second parallel pivot axes, said third frame member being fulcrumedon said first pivot pin portions for swinging about said first pivotaxis, means for causing such swinging of said third frame member, acarrier on said third frame member and movable thereon along saidguideway, a bending die on said carrier and rockably movable relative tosaid anvil die for bending the workpiece around the latter in responseto said swinging of said third frame member, yoke members having bearingslots therein, and means connecting said yoke members with said carrierand providing for adjustment of the yoke members on the carrier and inparallel planes extending transverse to said first pivot axis, saidsecond pivot pin portions extending into said bearing slots as fulcrumsfor said yokes and providing for swinging of said carrier about saidsecond pivot axis during the swinging of said third frame member aboutsaid first pivot axis.

14. A bending machine as defined in claim 13 and which includes adaptermembers detachably connected with said stationary frame member, andwherein said first and second pivot pin portions comprise portions ofsaid adapter members.

15. In a bending machine, a frame structure comprising stationary andmovable frame members, a pair of relatively movable work clamping diesmounted on said frame members and adapted for clamping engagement withopposite sides of a workpiece to be bent and one of which dies is ananvil die, means for actuating the movable frame member for causing saiddies to clamp the workpiece, a third frame member having a guidewaythereon, pivot means on said stationary frame member and comprisingeccentrically offset first and second pivot pin members providing firstand second parallel pivot axes, said third frame member being fulcrumedon said first pivot pin members for swinging about said first pivotaxis, means for causing such swinging of said third frame member, acarrier on said third frame member and movable thereon along saidguideway, a bending die on said carrier and rockably movable relative tosaid anvil die for bending the workpiece around the latter in responseto said swinging of said third frame member, yoke members having bearingslots therein, means connecting said yoke members with said carrier andproviding for adjustment of the yoke mem bers on the carrier and inparallel planes extending transverse to said first pivot axis, saidsecond pivot pin members extending into said bearing slots as fulcrumsfor said yoke members and providing for swinging of said carrier aboutsaid second pivot axis during the swinging of said third frame memberabout said first pivot axis, and means adjustably mounting said secondpivot pin members on said stationary frame member and providing forvariation of the eccentricity of said second pivot axis relative to saidfirst pivot axis.

16. A bending machine as defined in claim 15 and wherein the connectingmeans for said yoke members- References Cited in the file of this patentUNITED STATES PATENTS 383,047 Downes May 15, 1888 928,616 OBleness July20, 1909 935,299 Denham Sept. 28, 1909 1,029,012 Higgin June 11, 19122,299,537 Goldsmith et al. Oct. 20, 1942 2,568,691 I Wildman a Sept. 18,1951 2,596,848 Green May 13, 1952 FOREIGN PATENTS 76,795 Germany Aug.15, 1894

